Shaka! The walls fell?
A drawn out court battle would draw even more attention to these things. Something that is probably not in the interest of the RCC, so they pay in order to make it go away quickly and relatively quietly.
If they indeed fight an unjust accusation, it will further the connection in people's minds between them and pedophilia thanks to the hyperbolic way child porn is perceived in todays society. That is, even the possession of it. Anyone who has a few images is an active pedophile preying on our children, and so on.
A brief side point, (personal belief here), that logic fallacy would be like naming anyone who has the "faces of death" compilations is a murderer in waiting.
Anyway, that pedophilia has been documented to be true in many cases doesn't help the RCC's cause, and if they did fight it, they would be bound to follow that course of action every time this type of thing came up.
I don't think seeing a settlement as an admission of guilt in this case might be all that accurate.
After Goliath's defeat, giants ceased to command respect. - Freeman Dyson